Hello everyone. So I have officially figured out what is causing the pH fluctuations. The small reservoir size had to do with it, my plants being larger had to do with it, and the water softening process that this RO water is put through completely removes the buffering capacity.>>
https://www.icmag.com/ic/showthread.php?t=23357 >> this is a bit of a read, but anyone having the same problems as me should look into this article, as well as Root Aphids, which cause the exact same symptoms my plants have, but are by far more difficult to deal with than water.
I mix 1gal tap water to 2 gal filtered, which allows my pH to stay within 5.3-6.5 for 8 hours. It would probably stay within range for 24-48 hrs if I had a larger DWC unit, but since I have using storage totes that are 5 gal, instead of coolers that are 50 gal, I will have more issues with this. Anyone looking into DWC should NOT USE STORAGE BINS, unless you live in fucking Alaska or something, and your residual air temp is around 70 F, even with all your HID lights on. I am veggin with T5's, and the water temp is still scary. USE COOLERS, and make them big. A great example of keeping water temps down, and having a phenomenal harvest using DWC is BluBerry's DWC SCROG Round 2 Extrema.
https://www.rollitup.org/grow-journals/402585-dwc-scrog-grow-extrema-el.html
^ There's the first grow, his round 2 is currently in progress, but bluBerry has it down.
For my grow.. things still looking grim..
The firs pic is one of my clones that is turning yellow, the next is of one of my clones that is showing yellowing.. Not cool. There's another pics in here somewhere.. pic 4, another yellow clones (this uploader uploads them all out of order) the rest are pics of the girls in the BP, and MEgan in the hempy.. still looking bad. It is only a matter of time before she dies.. she probably only has like 10 leaves and branches left total. Maybe less than that